When we inject aer errors to the target pcie device by aer_inject module, the pci_ops of pci
bus which the target device is on will be assigned to pci_ops_aer.So if the target pci device
is a bridge, once we hot-remove and hot-add the bridge, the newly created child bus's pci_ops
will be assigned to pci_ops_aer too.Now every access to the child bus's devices will result to
system panic, because it get a NULL pci_ops in pci_read_aer/pci_write_aer.
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Reviewed-by: Sven Dietrich <Sven.Dietrich@xxxxxxxxxx>
---
drivers/pci/pcie/aer/aer_inject.c | 27 ++++++++++++++++++++++++++-
1 files changed, 26 insertions(+), 1 deletions(-)
diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
index 4e24cb8..0f00a27 100644
--- a/drivers/pci/pcie/aer/aer_inject.c
+++ b/drivers/pci/pcie/aer/aer_inject.c
@@ -109,6 +109,26 @@ static struct aer_error *__find_aer_error_by_dev(struct pci_dev *dev)
return __find_aer_error((u16)domain, dev->bus->number, dev->devfn);
}
+/* find pci_ops of the nearest parent bus */
+static struct pci_ops *__find_pci_bus_ops_parent(struct pci_bus *bus)
+{
+ struct pci_bus_ops *bus_ops;
+ struct pci_bus *pbus = bus->parent;
+
+ if (!pbus)
+ return NULL;
+
+ while (pbus) {
+ list_for_each_entry(bus_ops, &pci_bus_ops_list, list)
+ if (bus_ops->bus == pbus)
+ return bus_ops->ops;
+
+ pbus = pbus->parent;
+ }
+
+ return NULL;
+}
+
/* inject_lock must be held before calling */
static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus)
{
@@ -118,7 +138,9 @@ static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus)
if (bus_ops->bus == bus)
return bus_ops->ops;
}
- return NULL;
+
+ /* can't find bus_ops, fall back to get bus_ops of upstream bus */
+ return __find_pci_bus_ops_parent(bus);
}
static struct pci_bus_ops *pci_bus_ops_pop(void)
@@ -208,6 +230,7 @@ static int pci_read_aer(struct pci_bus *bus, unsigned int devfn, int where,
}
out:
ops = __find_pci_bus_ops(bus);
+ BUG_ON(!ops);
spin_unlock_irqrestore(&inject_lock, flags);
return ops->read(bus, devfn, where, size, val);
}
@@ -243,6 +266,7 @@ int pci_write_aer(struct pci_bus *bus, unsigned int devfn, int where, int size,
}
out:
ops = __find_pci_bus_ops(bus);
+ BUG_ON(!ops);
spin_unlock_irqrestore(&inject_lock, flags);
return ops->write(bus, devfn, where, size, val);
}
@@ -506,6 +530,7 @@ static struct miscdevice aer_inject_device = {
.fops = &aer_inject_fops,
};
+
static int __init aer_inject_init(void)
{
return misc_register(&aer_inject_device);
--
1.7.1
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